The instant invention provides methyl substituted-2-oxohexane derivatives and processes for preparing same which processes also include the production of C.sub.10 branched chain olefin epoxides, and processes for using a number of methyl substituted-2-oxohexane derivatives produced according to this invention for augmenting or enhancing the aroma of perfume compositions, colognes and perfumed articles. The methyl substituted-2-oxohexane derivatives of our invention are defined according to the structure: ##STR2## wherein R.sub.1 and R.sub.2 taken together represent oxygen; and wherein, taken alone, R.sub.1 represents hydroxyl and R.sub.2 represents methyl or R.sub.1 represents oxymagnesium halide and R.sub.2 represents methyl; and wherein R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 each represent the same or different methyl or hydrogen with the provisos that:
(i) the sum total of the carbon atoms of R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 is three;
(ii) when R.sub.7 is methyl, then R.sub.5 and R.sub.6 are each methyl; and
(iii) when R.sub.7 is hydrogen, then R.sub.3 or R.sub.4 is methyl.
Chemical compounds which can provide eucalyptus-like, fruity, hay-like and camphoraceous aromas with lime and pine undertones are highly desirable in the art of perfumery. Many of the natural materials which provide such fragrances and contribute such desired nuances to perfumery compositions and perfumed articles are high in cost, unobtainable at times, vary in quality from one batch to another and/or are generally subject to the usual variations in natural products.
There is, accordingly, a continuing effort to find synthetic materials which will replace, enhance or augment the fragrance notes provided by natural essential oils or compositions thereof. Unfortunately, many of the synthetic materials either have the desired nuances only to a relatively small degree or they contribute undesirable or unwanted odor to the compositions.
Aliphatic hydrocarbons are well known in the art of perfumery, e.g. myrcene, 2-methyl-6-methylene-2,7-octadiene, a constituent of lemon grass oil. Also found in lemon oil as well as in Bergamot oil, according to Gildemeister and Hoffman, (Die Atherischen Ole, 3rd edition, Volume 1, page 301) is octylene, a long chain olefin containing eight carbon atoms.
Arctander, "Perfume and Flavor Chemicals, (Aroma Chemicals)", 1969, Vol. I, at monograph 974, discloses the use of "di-isoprene" in perfumery. Arctander states that di-isoprene is a mixture of 2,6-dimethyl-2,6-octadiene; 2,7-dimethyl-2,6-octadiene; and 3,6-dimethyl-2,6-octadiene. Arctander states that this material has a sweet, diffusive, somewhat "gassy" odor and, overall, is of very "little interest to the perfumer". At monograph 1074, Arctander discloses "dipentene" having a use in perfumery and indicates that this "dipentene" is 1-methyl-4-iso-propenyl-1-cyclohexene and indicates that it is useful in perfumery as a "lift" in citrusy fragrances and in the reconstruction of many essential oils such as Bergamot, lime and lemon.
U.S. Pat. No. 3,896,180 issued on July 22, 1975 discloses the use in perfumery of the cyclic diene epoxide having the structure: ##STR3## particularly for its woody, amber odor.
Other mono-epoxidized products of tri-methylcyclododecatriene are disclosed in U.S. Pat. No. 3,723,478 issued on Mar. 27, 1973. The uses in perfumery of such materials are also disclosed in said U.S. Pat. No. 3,723,478.
Application for U.S. Letters Patent Ser. No. 184,132 filed on Sept. 4, 1980 (incorporated by reference herein) discloses the production of unsaturated branched ketones according to the reaction: ##STR4## wherein in each of the structures containing dashed lines, these structures represent mixtures of molecules wherein in each of the molecules, one of the dashed lines represents a carbon-carbon double bond and each of the other of the dashed lines represent a carbon-carbon single bond. These compounds so produced are indicated to be useful for their organoleptic properties in augmenting or enhancing the aroma or taste of consumable articles including perfume compositions and colognes. It is noteworthy that the compounds defined according to the structure: ##STR5## have unsaturation in the structure and, in addition, contain 12 carbon atoms rather than 10 carbon atoms. Disclosure of the resulting alcohols produced by reaction of these ketones with methyl magnesium halide is set forth in application for U.S. Letters Patent Ser. No. 212,887 filed on Dec. 4, 1980 (now U.S. Pat. No. 4,318,934 issued on Mar. 9, 1982). The resulting alcohols have 13 carbon atoms rather than the 11 carbon atom containing alcohols of the instant application.
Nothing in the prior art discloses compounds defined according to the generic structure: ##STR6## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are defined supra.
"Diisoamylene" is indicated to be synthesized in the following references:
(i) Murphy and Lane, Ind. Eng. Chem., Prod. Res. Dev., Vol. 14, No. 3, 1975, p. 167 (Title: Oligomerization of 2-Methyl-2-Butene in Sulfuric Acid and Sulfuric-Phosphoric Acid Mixtures).
(ii) Whitmore and Mosher, Vol. 68, J. Am. Chem. Soc., February, 1946, p. 281 (Title: The Depolymerization of 3,4,5,5-Tetramethyl-2-Hexene and 3,5,5-Trimethyl-2-Heptene in Relation to the Dimerization of Isoamylenes).
(iii) Whitmore and Stahly, Vol. 67, J. Am. Chem. Soc., December, 1945, p. 2158 (Title: The Polymerization of Olefins. VIII The Depolymerization of Olefins in Relation to Intramolecular Rearrangements. II).
(iv) U.S. Pat. No. 3,627,700, issued on Dec. 14, 1971, (Zuech).
(v) U.S. Pat. No. 3,538,181, issued on Nov. 3, 1970, (Banks).
(vi) U.S. Pat. No. 3,461,184 issued on Aug. 12, 1969 (Hay, et al).
(vii) Gurwitsch, Chemische Berichte, 1912, Vol. 2, p. 796 (Production of Di-isoamylene From Isoamylene Using Mercury Acetate Catalyst).
United Kingdom Pat. No. 796,130 published on June 4, 1958 discloses the synthesis of polyalkylindanes by means of, interalia, reacting alpha-methylstyrene with trimethylethene (2-methyl-butene-2) in the presence of an acid catalyst such as sulfuric acid or boron trifluoride methyletherate. It is further indicated that such compounds are useful intermediates in the production of perfumery compounds. Apparently, however, the more volatile diisoamylenes produced as side-products in the reaction of 2-methyl-butene-2 with alpha-methylstyrene are discarded.
The diisoamylene useful as a starting material in the instant case may be distilled from the reaction product (as see Example A infra) at a temperature in the range of 36.degree.-40.degree. C.; a liquid temperature in the range of 74.degree.-94.degree. C. and a pressure of 4-5 mm/Hg.